"Detour" is the fourth episode of the fifth season of the American science fiction television series The X-Files. It was written by executive producer Frank Spotnitz and directed by Brett Dowler. The episode aired in the United States on November 23, 1997, on the Fox network. The episode is a "Monster-of-the-Week" story, a stand-alone plot which is unconnected to the series' wider mythology. "Detour" received a Nielsen rating of 13.2, being watched by 22.8 million viewers, and received mixed reviews from television critics.
The show centers on FBI special agents Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) who work on cases linked to the paranormal, called X-Files. Mulder is a believer in the paranormal, while the skeptical Scully has been assigned to debunk his work. In this episode, Mulder and Scully, while traveling to a conference with two other FBI agents, stop at a roadblock and join a nearby investigation of attacks by an unidentified predator.
Executive producer Frank Spotnitz was inspired to write the episode after watching the 1972 American thriller film Deliverance. "Detour" took nineteen days to film, over eleven more than the norm for The X-Files. Shooting was hampered by incessant rain. The episode's villains were created through a mixture of elaborate "bark suits" and digital technology. In addition, the episode contained several cultural references.
Two men are surveying an area of the Apalachicola National Forest in Leon County, Florida when they are attacked and killed by unseen assailants with glowing red eyes. Later that day, Michael Asekoff and his son, Louis, are hunting for possums with their dog, Bo, in the same stretch of woods. Upon discovering a surveyor's bloody jacket, the father orders his son to take the dog and run home. As the son and dog take off, two shots are heard.
Meanwhile, Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) are carpooling with FBI agents Michael Kinsley and Carla Stonecypher en route to a "team building" seminar. When they are stopped at a roadblock by local police, Mulder decides to investigate. As Mulder and Scully venture into the woods, they are informed by Officer Michele Fazekas that no conclusive evidence has been found to support Louis' report of a shooting. Mulder sees this as a perfect opportunity to ditch the seminar. Later, Mulder explains to Scully that no species native to North America will attack a stronger member of its prey when there is a weaker target available.
At the Asekoff residence, Bo becomes upset and begins barking. Mrs. Asekoff lets him outside but when she attempts to retrieve him, the dog refuses to budge. She turns to go back inside but discovers that it has been bolted from the inside. Louis hears his mother's screams and climbs out of bed, but a dark, shadowy figure with red eyes corners him. Louis barely escapes through the dog door where he runs into Mulder, informing him of the creature's whereabouts in the house.
The next morning, Mulder shows Scully some tracks by the front door of the house that appear to be human. Based on the weight distribution, however, the assailant evidently travels on the balls of its feet rather than from heel to toe. Additionally, that the creature lured the mother out of the house in order to get to Louis suggests to Mulder that the creatures are paranormal in nature.
Jeff Glaser, a local technician armed with a FLIR device, joins Fazekas, Mulder, and Scully on a search for the creature. They soon spot two creatures on the FLIR which travel in separate directions, causing the four to split up. Fazekas is attacked and disappears. Mulder deduces from this that the creatures may be related to the Mothman of Point Pleasant, West Virginia. After a brief encounter with the creatures, Glaser takes off running and is swiftly killed by a creature. Mulder is grabbed by the other creature, though it releases him after Scully manages to wound it with her firearm.
The next morning, Scully falls through a hole into an underground chamber where the bodies of their missing companions are stored. Spotting a pair of red eyes, Scully realizes she does not have her firearm on her. Mulder drops his down to her as the bushes behind him begin to rustle. He jumps in the hole as Scully shoots the creature and kills it. As they examine the dead creature, they notice its almost human-like features and wood-like skin. Nearby, the words "Ad Noctum", Latin for "into darkness", are found carved into a tree trunk.
Mulder, Scully, Asekoff, and Fazekas are rescued, but there is no sign of Glaser or the other creature. Upon leaving the forest, Mulder states that the creature may, in fact, be an evolved version of the first Spanish conquistadors who had first settled in the forest 450 years before. Although Kinsley finds it ridiculous, Mulder believes that centuries of seclusion could be adequate for such drastic adaptations to happen. Afterwards, Mulder realizes that the creatures presume others' presence in their territory as threatening and rushes to the hotel room where Scully is packing her things. After ascertaining that she is finished packing, he firmly urges her to vacate the room, which she does. The camera then pans under the bed where a pair of red eyes open.
Executive producer Frank Spotnitz was inspired to write the episode after watching the 1972 American thriller film Deliverance. Spotnitz recounted, "the idea of being stranded in a hostile environment is very interesting to me and so is the idea of something moving the brush that you can't see." Series writer Vince Gilligan contributed to the "team builder" exercise bit. The ending was left intentionally ambiguous. Spotnitz explained, "it's scarier if you think [the monster] could still be out there."
Initially, scenes were filmed at the Seymour Demonstration Forest in North Vancouver. Although the typical shooting time for an episode of The X-Files is eight days, "Detour" took nineteen days to film. Second unit director Brett Dowler later recounted that it "rained every day". This put a strain on the cast and crew because almost every main shot needed was intended to be outdoors in the daylight. Because of the massive delays, changes were made: the actors' schedules were rearranged and Kim Manners was brought in to assist Dowler in finishing the second unit of the episode. Filming later moved to a soundstage to avoid the incessant rain. Spotnitz later noted that "I thought I'd come up with a very simple concept. Literally, one that was easy for the props people and all the other departments."
Initially, it was decided that the antagonists of the episode would be dressed in elaborate "bark suits" so that they would blend into their surroundings. Special effects supervisors Toby Lindala created several elaborate suits made from faux bark. In the end, however, difficulties were so great that the show switched to digital effects. Visual effects supervisor Laurie Kallsen-George was tasked with creating the glowing red eyes. Kallsen-George digitized and blended various "eyeball images"—including shots of her family's dog.
"Detour" premiered on the Fox network on November 23, 1997. This episode earned a Nielsen rating of 13.2, with a 19 share, meaning that roughly 13.2 percent of all television-equipped households, and 19 percent of households watching television, were tuned in to the episode. It was viewed by 22.8 million viewers.
"Detour" received mixed to positive reviews from critics. Francis Dass of New Straits Times was positive toward the episode, calling it "imaginative". IGN named it the seventh best standalone X-Files episode of the entire series. The site called the sequence wherein "Scully holds a wounded Mulder and sings 'Jeremiah was a Bullfrog' [sic]" the "best scene" of the episode and praised the depth of the characters' relationship. Zack Handlen from The A.V. Club gave the episode an A and called it a "solid" entry in the series. Handlen complimented the episode's cold opening, structure, monster, and the relationship between Mulder and Scully; writing that the "core relationship" between Mulder and Scully "was remarkably strong". He also noted that their conversation in the woods was reminiscent of the third season episode "Quagmire" and was "sweet". Jonathan Dunn, writing for What Culture, highlighted "Detour" for its cinematic appeal and included it in the "5 Episodes [of The X-Files] That Could Be Made Into Movies" list.
Other reviews were more mixed. John Keegan from Critical Myth gave the episode a 7 out of 10, and wrote "Overall, this episode is a somewhat light-hearted departure from the mythology installments and out-of-continuity flights of fancy that would dominate the early fifth season. While the character-driven moments are a highlight, the actual 'case' is far from special, often digressing from its purpose as a trigger for the character work. In the end, it’s fairly average." Paula Vitaris from Cinefantastique gave the episode a mixed review and awarded it two stars out of four. She called the scene featuring Scully singing to Mulder "a failed attempt to create 'a special X-Files moment'" and noted that the sequence was "a poor substitute for meaningful dialogue". Vitaris, however, did applaud the guest cast and called the creature's effects "very creepy". Robert Shearman and Lars Pearson, in their book Wanting to Believe: A Critical Guide to The X-Files, Millennium & The Lone Gunmen, rated the episode two stars out of five. The two noted that it replicated "Quagmire" too much for its own good and was "satisfied with the intention alone". They reasoned that because "it's so busy telling us how cute the interplay" between Mulder and Scully is, the episode "forgets to make it any good". Shearman and Pearson also called the Spanish conquistador revelation "so utterly left field it feels self-parodic."